Expert hands altered path

- Computer code gibberish for non-aviators

Flight MH370’s captain Zaharie Ahmad Shah. Programs from the simulator found at the captain’s home included runways in southern India, the Maldives, Sri Lanka, Diego Garcia, the US and Europe. Such flight simulators usually show hundreds or even thousands of runways, an official said, cautioning against jumping to hasty conclusions. (Reuters)
n See Page 2

Washington, March 18: The first turn to the west that diverted the missing Malaysia Airlines plane from its planned flight path to Beijing was carried out through a computer system that was most likely programmed by someone in the plane’s cockpit, according to US officials.

Instead of manually operating the plane’s controls, whoever altered the flight path typed seven or eight keystrokes into a computer on a knee-high pedestal between the captain and the first officer, the officials said.

The flight management system, as the computer is known, directs the plane from point to point specified in the flight plan submitted before a flight. It is not clear whether the path was reprogrammed before or after the take-off.

The fact that the turn away from Beijing was programmed into the computer has reinforced the belief of investigators that the plane was deliberately diverted. It has also increased their focus on the pilots.

Investigators are scrutinising radar tapes from the time the plane first departed Kuala Lumpur because they believe the tapes will show that after the plane first changed its course, it passed through several pre-established “waypoints”, which are like virtual mile markers in the sky.

That would suggest the plane was under control of a knowledgeable pilot because passing through those points without using the computer would have been unlikely.

According to investigators, it appears that a waypoint was added to the planned route. Pilots do that in the ordinary course of flying if air traffic controllers tell them to take a different route, to avoid weather or traffic. But in this case, the waypoint was far off the path to Beijing.

Whoever changed the plane’s course would have had to be familiar with Boeing aircraft, though not necessarily the 777 — the model that disappeared. American officials and aviation experts said it was far-fetched to believe that a passenger could have reprogrammed the flight management system.

The normal procedure is to key in a five-letter code — gibberish to non-aviators — that is the name of a waypoint. A normal flight plan consists of a series of such waypoints, ending in the destination airport.

One of the pilots keys in a waypoint on a separate screen known as a scratchpad, and after confirming that it has no typographical errors, pushes another button to move it into the sequence already in the flight plan. The normal practice is to orally confirm the waypoint with the other pilot, then push another button to instruct the airplane to go there.

With the change in course, the plane would bank at a comfortable angle, around 20 degrees, and make the turn. Passengers would not feel anything unusual.